This invention relates to an apparatus useful for studying cells in culture under conditions which reproduce their natural, in vivo mechanical environment. Use of the apparatus of this invention enables one to study the changes in the biochemistry and physiology of cultured cells under conditions of mechanical strain as compared to cells grown conventionally under quiescent conditions.
Mechanical stimulation of cells is believed to influence the biochemistry and physiology of cells, in particular, enhanced production and, therefore, improved harvesting efficiency of biochemical products from these cells. Various systems have been proposed previously for growing cells in culture. A few systems have attempted to account for the natural mechanical environment of cells. One typical prior art system (Leung, D., et al, Science 191:475-477, 1976), attempts to uniaxially elongate smooth muscle cells in culture, but fails in three general categories, namely, (1) uniaxial stretch is not physiologic, (2) the system does not allow for microscopic visualization of the cells, and (3) the strain distribution in this system is not uniform and, therefore, not well-characterized for the population of cells stimulated.
In another typical prior art system (Davies, P. et al, J. Clin. Invest. 73:1121-1129, 1984), cells in culture are subjected to a uniform shear strain, constant in magnitude and direction. This system fails in two general areas, namely, (1) endothelial cells are the only cells subjected to shear strain in vivo thereby limiting its applicability to only this one cell type and (2) shear strain in vivo occurs simultaneously with biaxial tension, and, by uncoupling the two, the true mechanical environment of endothelial cells is not reproduced.